Spatial distribution of glutathione, glutathione-related and antioxidant enzymes in cultured mouse embryos

The present study was undertaken to evaluate the detoxifying capacity of organogenesis-stage murine concepti cultured in vitro. Investigative attention was particularly focused on the embryonic tissue distribution of cytoprotective pathways. Glutathione (GSH) status, GSH-related and antioxidant enzymes were assayed in the embryo proper (EP), visceral yolk sac (VYS) and ectoplacental cone (EC) of 29.44 ± 1.56 (mean ± SD) somite pairs concepti. All the tissues displayed significant and comparable concentrations of GSH, further supporting this tripeptide as critical in protection against embryotoxicants. The totality of enzymatic activities was detectable in the selected embryonic compartments. In terms of spatial distribution analysis, maximal activities were found in EC (glutathione peroxidase, glutathione reductase, superoxide dismutase and glyoxalase I and II), and VYS (glutathione transferase and catalase). These results indicate: (1) the organogenesis-stage conceptus, in addition to significant amounts of GSH, expresses constitutive activities of GSH-related and antioxidant enzymes; (2) maximal activity levels are detectable in the embryonic sites which, at the developmental stage selected for assay, serve (VYS) or are evolving to serve (EC) embryo/maternal exchange, and thus represent the primary sites of interaction with foreign compounds. Received: 13 March 1997 / Accepted: 18 August 1997     

Responses of antioxidant system in Arabidopsis thaliana suspension cells to the toxicity of microcystin-RR

Microcystins are cyclic heptapeptide hepatoxins produced by many species of cyanobacteria. The toxic effects and mechanism of microcystins on animals have been well studied both in vivo and in vitro. It was also reported that microcystins had adverse effects on plants. However, to our knowledge, there is no information about the toxic effects and mechanism of microcystins on plant suspension cells. In this study, Arabidopsis thaliana suspension cells were exposed to a range dose of microcystin-RR. Lipid peroxidation, a main manifestation of oxidative damage, was studied and a time- and dose-dependent increase in malondiadehyde was observed. In contrast, glutathione (GSH) levels in the cells decreased after 48 h treatment with 1 and 5 mg/L of microcystin-RR. The activities of superoxide dismutase (SOD) and catalase (CAT) increased significantly after 48 h exposure to 1 and 5 mg/L of microcystin-RR, but glutathione S-transferase (GST) activity showed no difference compared with the control. These results clearly indicate that microcystin-RR is able to cause oxidative damage in A. thaliana suspension cells. Decrease of GSH content and increases of SOD and CAT activities reveal that the antioxidant system may play an important role in eliminating or alleviating the toxicity of microcystin-RR. The possible toxicity mechanism of microcystin-RR on the A. thaliana suspension cells is also discussed in this paper.     

Responses of antioxidant systems in the hepatocytes of common carp (Cyprinus carpio L.) to the toxicity of microcystin-LR.

The freshwater, bloom-forming cyanobacterium (blue-green alga) Microcystis aeruginosa produces a peptide hepatotoxin, which causes the damage of animal liver. Recently, toxic Microcystis blooms frequently occur in the eutrophic Dianchi Lake (300 km2 and located in the South-Western of China). Microcystin-LR from Microcystis in Dianchi was isolated and purified by high performance liquid chromatography (HPLC) and its toxicity to mouse and fish liver was studied (Li et al., 2001). In this study, six biochemical parameters (reactive oxygen species, glutathione, superoxide dismutase, catalase, glutathione peroxide and glutathione S-transferase) were determined in common carp hepatocytes when the cells were exposed to 10 microg microcystin-LR per litre. The results showed that reactive oxygen species (ROS) contents increased by more than one-time compared with the control after 6 h exposure to the toxin. In contrast, glutathione (GSH) levels in the hepatocytes exposed to microcystin-LR decreased by 47% compared with the control. The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxide (GSH-Px) increased significantly after 6 h exposure to microcystin-LR, but glutathione S-transferase (GST) activity showed no difference from the control. These results suggested that the toxicity of microcystin-LR caused the increase of ROS contents and the depletion of GSH in hepatocytes exposed to the toxin and these changes led to oxidant shock in hepatocytes. Increases of SOD, CAT and GSH-Px activities revealed that these three kinds of antioxidant enzymes might play important roles in eliminating the excessive ROS. This paper also examined the possible toxicity mechanism of microcystin-LR on the fish hepatocytes and the results were similar to those with mouse hepatocytes.     

Effect of exercise training on antioxidant system in brain regions of rat

The purpose of this investigation was to determine whether any alterations in antioxidant enzyme activities and levels of glutathione (GSH) in brain regions occurred following exercise training. Sprague-Dawley rats were given exercise training on a treadmill for 7.5 weeks and sacrificed 18 h after the last exercise along with the sedentary control rats. Different brain regions—cerebral cortex (CC), brainstem (BS), corpus striatum (CS), and hippocampus (H)—were isolated; GSH, oxidized glutathione (GSSG), Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were determined. The exercise training increased SOD activity significantly (130% of sedentary control) in BS and in CS. SOD activity in H was the lowest of all four brain regions. Different brain regions showed GSH-Px activity in decreasing order for CS < BS < CC < H. GSH levels were 43% less in BS than CC and CS. The ratio of GSH/ GSSG significantly increased from 6.8 to 8.3 in CC, and from 9.4 to 13.5 in BS as a result of exercise training. Different brain regions contained different activities of antioxidant enzymes, as well as GSH and GSSG levels, which were preferentially altered as a result of exercise training to cope with oxidative stress.     

Capsaicin prevents ethanol-induced teratogenicity in cultured mouse whole embryos

Prenatal exposure to alcohol promotes the level of reactive oxygen species within embryos and results in developmental disorders. In this study, we investigated the effect of capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide), the major pungent ingredient in red peppers, on ethanol-induced teratogenicity in mouse embryos (embryonic days 8.5-10.5). In response to ethanol administration (1.0 microl/ml), developmental parameters such as yolk sac circulation, allantois, heart, hindbrain, midbrain, forebrain, otic and optic systems, branchial bar, olfactory system, forelimb, hindlimb, and somites decreased significantly in comparison with those of control group (p<0.05). However, the concurrent administration of capsaicin (1 x 10(-8) microg/ml or 1 x 10(-7) microg/ml) and ethanol significantly ameliorated most of the morphological scores excepting yolk sac circulation and hindlimb scores (p<0.05). Furthermore, the levels of superoxide dismutase activity and cytoplasmic glutathione peroxidase and phospholipid hydroperoxide glutathione peroxidase mRNAs in the ethanol-treated embryos recovered to the levels observed in control embryos by capsaicin co-administration. These results indicate that capsaicin has a protective effect against ethanol-induced teratogenicity via an antioxidative activity.     

Glutathione and glutathione-related enzyme activities of male and female rat hepatocytes under various culture conditions

 The effect of culture medium on glutathione (GSH) dependent detoxification defence system of primary cultured hepatocyte from either male or female rats was studied. Intracellular reduced (GSH) and oxidized glutathione (GSSG), and six GSH-related enzyme activities, including GSH peroxidase (GSH Px), GSH reductase (GSH Rd), cytosolic GSH S-transferase (cGST), microsomal GSH S-transferase (mGST), γ-glutamyl transpeptidase (GTP), and γ-glutamylcysteine synthetase (GCS), were investigated during a 6-day culture. Media free of fetal bovine serum (FBS) and with 2.5 or 10% FBS were used. Whatever the medium, there was an initial increase of intracellular GSH and GSSG, a threefold increase of GSH at day 3 and fourfold increase of GSSG at day 4, later decreasing to their original level at day 6. The activities of all six GSH-related enzymes of male and female hepatocytes remained relatively stable during the first 72 h, then gradually decreased to 50–80% of initial activities. With the exception of cGST, time-course profiles of other enzyme activities were not significantly different among various media. In both sexes, higher cGST activity was maintained for cells cultured in the presence of FBS. Results of immunoblotting analysis of cytosolic GST isozymes indicate that the placental form of GST (Yp) was markedly increased after plating and the extent of increase of Yp was higher in the presence of FBS. Despite the culture medium, the level of GST isoform Ya was maintained steadily for 6 days, however, Yb was maintained during the first 3 days and then decreased. In terms of the gender difference, GSH Px and GTP activities of hepatocytes from females were significantly greater than of males over the entire culture period. Results indicate that FBS seems not to be absolutely essential in maintaining GSH level and most of the GSH-related enzyme activities in rat hepatocytes. Furthermore, GSH levels and GSH-related enzyme activities of hepatocytes from female rats were similar to those from male rats. Received: 10 January 1996/Accepted: 3 May 1996     

Dual protective role for Glutathione S-transferase class pi against VCD-induced ovotoxicity in the rat ovary

The occupational chemical 4-vinylcyclohexene diepoxide (VCD) selectively destroys ovarian small pre-antral follicles in rats and mice via apoptosis. Detoxification of VCD can occur through glutathione conjugation, catalyzed by glutathione S-transferase (GST) enzymes. Further, GST class pi (GSTp) can negatively regulate JNK activity through protein:protein interactions in extra-ovarian tissues. Dissociation of this protein complex in the face of chemical exposure releases the inhibition of pro-apoptotic JNK. Increased JNK activity during VCD-induced ovotoxicity has been shown in isolated ovarian small pre-antral follicles following in vivo dosing of rats (80 mg/kg/day; 15 days, i.p.). The present study investigated the pattern of ovarian GSTp expression during VCD exposure. Additionally, the effect of VCD on an ovarian GSTp:JNK protein complex was investigated. PND4 F344 rat ovaries were incubated in control medium ± VCD (30 μM) for 2-8 days. VCD increased ovarian GSTp mRNA (P < 0.05) relative to control on d4-d8; whereas GSTp protein was increased (P < 0.05) on d6-d8. A GSTp:JNK protein complex was detected by immunoprecipitation and Western blotting in ovarian tissues. Relative to control, the amount of GSTp-bound JNK was increased (P = 0.09), while unbound JNK was decreased (P < 0.05) on d6 of VCD exposure. The VCD-induced decrease in unbound JNK was preceded by a decrease in phosphorylated c-Jun which occurred on d4. These findings are in support of a possible dual protective role for GSTp in the rat ovary, consisting of metabolism of VCD and inhibition of JNK-initiated apoptosis.     

结缔组织病患者血清脂质过氧化物及抗氧化水平的研究

目的探讨血清超氧化物岐化酶(SOD)、丙二醛(MDA)、维生素C(Vit-C)、维生素E(Vit-E)浓度变化与结缔组织病(connectivetissuedisease,CTD)的关系。方法本实验以化学比色法分别检测了99例CTD患者的血清SOD、MDA、维生素C、维生素E的浓度,与正常对照组进行了比较。其中系统性红斑狼疮(SLE)患者活动期与非活动期进行了比较。结果99例CTD患者,其中系统性红斑狼疮组(SLE)23例,原发性干燥综合征组(SS)21例,类风湿性关节炎组(RA)20例,混合结缔组织病组(MCTD)13例,多发性肌炎组(PM)13例,进行性系统性硬化症组(PSS)9例,各CTD组血清MDA浓度较正常对照组增高(P<0.01),其中SLE活动期MDA浓度较非活动期增高(P<0.01)。而各组血清SOD、维生素C、维生素E浓度较正常对照组降低(P<0.001、P<0.05、P<0.001),其中SLE活动期血清SOD、维生素C、维生素E浓度也较非活动期下降(P<0.01,P<0.05,P<0.05)。结论血清SOD、MDA、维生素C,维生素E水平的变化与CTD的发生发展及SLE的活动性有关。血清MDA水平升高,SOD、维生素C、维生素E抗氧化水平降低是CTD的危险因素。     

Effect of N-acetylcysteine administration on the expression and activities of antioxidant enzymes and the malondialdehyde level in the blood of lead-exposed workers

We investigated whether treatment with N-acetylcysteine (NAC) reduces oxidative stress intensity and restores the expression and activities of superoxide dismutase (Sod1, SOD), catalase (Cat, CAT) and glutathione peroxidase (Gpx1, GPx) in lead-exposed workers.The exposed population was divided randomly into two groups. Workers in the first group (reference group, n = 49) were not administered any drugs, while workers in the second group (n = 122) were treated with NAC at three doses for 12 weeks (200 mg, 400 mg, 800 mg/day).NAC administered orally to lead-exposed workers normalized antioxidant enzyme activities in blood cells. Oxidative stress intensity measured as malondialdehyde (MDA) levels in serum, leukocytes and erythrocytes significantly decreased after NAC administration. NAC may be an alternative therapy for chronic lead intoxication.     

Sex differences in the cellular defence system against free radicals from oxygen or drug metabolites in rat

In this study, it was investigated whether sex-related differences in the protective mechanisms against oxygen radicals and free radical metabolites from drugs were present in rat liver, heart, and kidney. To that end, superoxide dismutase, catalase, the factors of the glutathione system and vitamin E were measured. In addition, NADPH-dependent cytochrome c-reductase activity was established, as this enzyme is involved in the formation of free radicals in the presence of many xenobiotics. The total capacity of the cellular systems that detoxify reactive oxygen species or free radical-drug metabolites seems to be higher in female liver as compared to male. No differences were found for heart and kidney tissue. It is hypothesized that female rats probably are less vulnerable for those drugs whose hepatotoxic action is induced by excessive formation of free radical species.     

Acute or repeated cocaine administration generates reactive oxygen species and induces antioxidant enzyme activity in dopaminergic rat brain structures

Either a single (acute) or repeated daily (chronic) injections (1 injection/day) of 20 mg/kg cocaine for 10 days to rats was found to increase reactive oxygen species production in two dopaminergic brain structures, the frontal cortex and the striatum. We found that the mitochondrial genome was down-regulated after acute cocaine injection. Hydroperoxide and lipid peroxide generation was correlated with an increase in mitochondrial hydrogen peroxide generation and with a reduced functioning of mitochondrial complex I in response to cocaine. As judged from the measurement of caspase-3 activity and TUNEL labeling, neither acute nor chronic cocaine treatment has been found to induce apoptosis in any of the structures examined. This differs dramatically from what has been described for methamphetamine. Cocaine-induced radical formation was accompanied by the induction of the antioxidant enzymes superoxide dismutase and glutathione peroxidase, after both acute and chronic cocaine treatment. In addition, proteasome chymotrypsin-like activity was enhanced following a single cocaine injection in both cortex and striatum. It is proposed that the compensatory mechanisms to oxidative stress occurring in response to cocaine were effective in scavenging reactive oxygen species and in preventing subsequent cellular damage, thus explaining why no significant cell death was found in these brain structures.     

The effect of curcumin as an antioxidant on cochlea fibroblasts in ototoxic rat models

Aminoglycosides (e.g. Gentamicin) are ototoxic drugs and widely prescribed due to their effective antimicrobial actions and affordable prices. This study focused on determining protective effect of curcumin against the damage caused by aminoglycosides. We aimed to demonstrate the potential of curcumin as an antioxidant to increase the expressions of superoxide dismutase (SOD) in fibroblasts of cochlea lateral wall in ototoxic rat models. The experiment was conducted with randomized post test-only control group design by using 32 male Rattusnorvegicus adults which received a combination of gentamicin and curcumin with different durations and doses. Then, the rats underwent terminations and immunohistochemical assay to determine the expression of SOD. The rats receiving gentamicin injection showed significantly decreased expression of SOD (P<0.05), and the administration of curcumin before and after the gentamicin injection showed significantly increased expression of SOD (P<0.05). Collectively, we showed that curcumin was an antioxidant against oxidative stress due to ototoxicity evidenced by the expression of SOD.     

Cisplatin nephrotoxicity in lead-pretreated rats: enzymatic and morphological studies

Treatment of rats with cisplatin or with cisplatin after chronic pre-exposure to lead induced a decrease in cytochrome P-450, reduced glutathione (GSH), GSH-S-transferase, reductase and peroxidase activities, and an increase in N-glucuronyl transferase, lipid peroxidation and oxidized glutathione (GSSG). On histological examination, rats treated by lead or cisplatin and by lead + cisplatin revealed significant proximal tubular lesions which varied from minimal changes to severe necrosis. Lead toxicity was characterized by irregularity and thickening of glomerular basement menbranes, and by tubular mitochondrial alterations associated with the presence of intranuclear inclusions. Cisplatin injury showed more extensive lesions with cellular disorganization. Except for an increase in N-glucuronyl transferase activity, lead did not exert any significant effect on these biochemical and histological parameters and did not significantly modify the deleterious effects of further therapy by cisplatin.     

Effect of treatment with vitamin D plus calcium on oxidative stress in streptozotocin-induced diabetic rats

Background

In diabetes mellitus, uncontrolled hyperglycemia has been reported to induce oxidative stress, which may lead to health complications. Vitamin D, however, acts as a non-enzymatic antioxidant to protect cells against oxidative stress and damage.

气态甲醛与三氯乙烯联合暴露染毒对小鼠脾脏的脂质过氧化作用

目的探讨气态甲醛、三氯乙烯联合暴露染毒对小鼠脾脏的脂质过氧化作用及二者联合作用的类型。方法选择健康清洁级昆明种小鼠108只,按3×3析因设计随机分为9组,设甲醛(0、1、5 mg/m3)和三氯乙烯(0、1 000、5 000 mg/m3)单独以及二者联合染毒组,采用静式吸入染毒法染毒,每天2 h,连续14 d。染毒结束后测定小鼠脾脏的总超氧化物歧化酶(SOD)活力、谷胱甘肽过氧化物酶(GSH-PX)活力和丙二醛(MDA)含量。结果小鼠脾脏SOD和GSH-PX活力随甲醛、三氯乙烯染毒剂量的升高而明显下降,MDA含量则明显升高,差异均有统计学意义(P<0.05)。结论气态甲醛、三氯乙烯吸入染毒对小鼠脾脏具有氧化损伤作用,两者联合可能存在一定的交互作用。     

拟人参皂苷F11对甲基苯丙胺依赖大鼠的血清及脑组织中氧化物的影响

目的 观察拟人参皂苷F11(PF11)对甲基苯丙胺(MA)依赖大鼠脑组织中氧化物质的干预,探讨PF11对MA依赖大鼠脑损伤的保护作用.方法 采用剂量递增法建立MA依赖大鼠模型,分别ig大鼠3、6 mg·kg-1PF11,连续12d,第13天断头取血、脑,观察各组大鼠血清及脑组织中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、丙二醛(MDA)含量的变化.结果 MA依赖大鼠血清及脑组织海马区MDA的含量显著升高,SOD、GSH-Px的活力下降,与对照组有显著差异;与模型组比较,PF116 mg·kg-1组的脑组织海马区MDA的含量显著降低,SOD、GSH-Px的活力显著升高.结论 PF11能降低MA染毒大鼠脑组织海马区MDA的含量,升高SOD、GSH-Px的活力,通过抗氧化作用对脑组织损伤有较好的干预与保护作用.     

Changes of the activities of superoxide dismutase after exposure to the fume of heavy metals and the significance of zinc in the tissue

Pathological changes induced by cadmium aerosol had features common to the changes evoked by oxidants. Female rats were exposed to fumes of lead, antimony, zinc and cadmium (15–100 nmoles/m³). One hour after termination of exposure, superoxide dismutase (SOD) activity in erythrocytes of the exposed rats lowered by 15–40%. SOD activity of lung lavage fluid also lowered by 20–35% at the 2nd day after the exposure. The inverse value of SOD activity (l/SOD) in erythrocytes and of lung lavage fluid were proportional to the molar exposure level adjusted by the particle size (Dixon plot), irrespective of the difference of the exposed substance. The ratio of dry weight to wet weight of the lung was 4.3–26% lower than the control value on the later period after the exposure. With the heavy metal exposure, the uptake of the exposed metal was found to be proportional to the endogenous zinc concentration, which was correlated well with the change of SOD in the lung and in erythrocytes. Cadmium decreased the zinc concentration after the exposure.     

Diallyl disulfide ameliorates gentamicin-induced oxidative stress and nephropathy in rats

Experimental evidences suggest a role of reactive oxygen species in gentamicin-induced nephropathy in rats. Therefore, we investigated if diallyl disulfide, a garlic-derived compound with antioxidant properties, has a renoprotective effect in this experimental model. Four groups of rats were studied: (1) control, (2) gentamicin treated subcutaneously with gentamicin (70 mg/kg/12 h/4 days), (3) diallyl disulfide treated intragastrically with diallyl disulfide (50 mg/kg/24 h/4 days), and (4) gentamicin + diallyl disulfide treated with gentamicin + diallyl disulfide. Gentamicin induced (a) nephrotoxicity, (b) increase in renal oxidative stress, and (c) decrease in the activity of manganese superoxide dismutase, glutathione peroxidase, and glutathione reductase. Diallyl disulfide ameliorated these changes induced by gentamicin. The mechanism by which diallyl disulfide has a renoprotective effect in gentamicin-induced acute renal failure in rats may be related, at least in part, to the amelioration in the oxidative stress and the preservation in the activity of the antioxidant enzymes in kidney.     

侵蚀性葡萄胎患者化疗前后血清SOD、LPO、GSH-PX含量变化及其临床意义

目的　观察侵蚀性葡萄胎患者化疗前后血清 SOD、L PO、GSH- PX含量的变化。方法　分别应用放免法和生化法对 3 3例侵蚀性葡萄胎患者进行了化疗前后血清 SOD、L PO、GSH- PX含量检测 ,并与 3 0名正常健康人作对照。结果　侵蚀性葡萄胎患者化疗前血清 SOD、GSH- PX水平明显低于正常人组 ( P<0 .0 1) ,而 L PO则明显高于正常人组 ( P<0 .0 1) ,化疗 6个月后复发者 SOD、L PO、GSH- PX水平持续异常 ,未复发者 SOD、L PO、GSH- PX水平接近正常。结论　侵蚀性葡萄胎患者血清 SOD、L PO、GSH- PX含量的变化与患者的预后密切相关     

首发精神分裂症患者脂质过氧化物及抗氧化酶水平的研究

目的：探讨氧化应激在精神分裂症发病中的作用。方法：对首发且未服药的精神分裂症患者40例,行简明精神病评定量表（BPRS）评定,并测定氧化应激相关指标。药物治疗12周后,再次进行上述检测。取40例健康志愿者外周血,检测相同生化指标。结果：患者组丙二醛（MDA）和过氧化氢酶（CAT）较对照组显著升高（P〈0.01）,而超氧化物歧化酶（SOD）及谷胱甘肽过氧化物酶（GSH-Px）显著降低（P〈0.01）。治疗后MDA和CAT较治疗前显著降低（P〈0.01）,而SOD及GSH-Px显著升高（P〈0.01）。结论：精神分裂症患者处于氧化应激状态,自由基增加,抗氧化能力降低,这些可能与精神分裂症的病理机制有关。